Date: Wed, 03 Feb 1999 20:41:47 -0700 From: Drew Eckhardt <drew@Poohsticks.Org> To: Katsushi Kobayashi <ikob@koganei.wide.ad.jp> Cc: hardware@FreeBSD.ORG Subject: 1394/DV comments, capture program, mailing list Message-ID: <199902040341.UAA03651@chopper.poohsticks.org> In-Reply-To: Your message of "Wed, 27 Jan 1999 15:46:37 %2B0900."
next in thread | raw e-mail | index | archive | help
On Wed, 27 Jan 1999 15:46:37 +0900, Katsushi Kobayashi <ikob@koganei.wide.ad.jp> wrote:
>But, my driver will be helpful some people for following purposes:
>
>- To use DV equipements.
I have both professional and personal interests in DV (I use a helmet
mounted PC1 for sports video), and would love to play with it on my
unix boxen although there are a few impediments:
1. Matsushita (Panasonic) has patents applicable to anything which
extracts video and/or audio from the a DV data stream (see US
Patent 5,691,819) as well as ones on the most obvious techniques
for transcoding to DV.
This is a huge impediment to bazaar style development of most unix DV
software, and it would be wonderful if you or some one else in geographic
proximity to them were to work out some sort of compatable licensing
agreement. As of 1997, their General Manager of Intellectual Property was
Mr. R. Shimizu
c/o<A0> AVC Products Development Lab<A0>
2-15 Matsuba-cho, Kadoma-shi
Osaka 571
Japan
FAX: +81-6-905-5408
2. Patent issues aside, to do anything really fun with DV you
need documentation (the shuffling algorithm, code book,
quantization tables), with the obvious source being the
"Blue Book". Unfortunately, that carries a 50,000 yen price tag
(about $440 USD at the current exchange rates).
Fortunately, the subset of it embodied by DVCPRO/D7 (locked audio,
4:1:1 sampling on both NTSC and PAL) is described in the affordable
($55) SMPTE 306m standard.
3. You also need to get the data to disk. I poked at the problem for
parts of two evenings (write() often blocks long enough to cause dropped
packets), and came up with the following program
ftp://ftp.poohsticks.org/dv/capture-0.1.tar.gz
which captures a user-specified number of DV frames off a Lynx board.
In theory, PAL should work too although for obvious reasons I've only
tested NTSC.
The two process write behind code needed to avoid dropped packets is C++,
and the DV structure definitions use __attribute__((packed)) so egcs is
needed to compile it.
With a few changes to capture based on time code and with a matching
output program, this will make it possible to do assemble edits separated
by simple cuts.
4. I find this interesting, have seen a handful of comments on the dv
mailing list regarding dv under unix, and have set up a mailing list
for discussing the technical and legal issues of dv under free unicies
frunix-dv-request AT poohsticks DOT org
To Unsubscribe: send mail to majordomo@FreeBSD.org
with "unsubscribe freebsd-hardware" in the body of the message
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?199902040341.UAA03651>